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Journal of Energy in Southern Africa

versión On-line ISSN 2413-3051
versión impresa ISSN 1021-447X

J. energy South. Afr. vol.19 no.1 Cape Town  2008


Electrical and thermal analysis of an asynchronous machine for application in wind energy generation



O I OkoroI; E ChikuniII

IUniversity of Nigeria, Nsukka
IIPolytechnic of Namibia, Windhoek, Namibia




The electromagnetic (electrical) and mechanical design of an Asynchronous machine for application in wind energy generation depends on the knowledge of heat transfer within the various parts of the machine. Unfortunately, the analysis of thermal effect in Asynchronous motors is usually more complex, more non-linear and more difficult than the electromagnetic behaviour. This paper therefore, sets out to investigate the effect of coupling the electrical model with the thermal model of the machine. The results of the analysis show that the proposed coupled model is capable of predicting the stator phase currents, rotor bar temperature, stator windings temperature, heat losses, rotor speed and electromagnetic torque of the test machine under dynamic conditions and at rated load operation. The analysis finds application in wind energy generation especially when modified and applied to synchronous generators. By so doing, the prediction of critical temperatures of machine parts can be achieved prior to machine operation.

Keywords: asynchronous machine, electrical model, thermal model, coupling, wind energy, dynamic behaviour



Full text available only in pdf format.



The first author wishes to thank Prof. Dr.-Ing. B. Weidemann for his useful discussion on the subject and to DAAD for their financial assistance during the research work at the University of Kassel, Germany.



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Received 26 April 2007
Revised 31 January 2008